Conventionally, battery packs have been used as power supplies for, for example, electric tools. The battery packs are charged by a dedicated charging apparatus. The battery packs used for electric tools have a large battery capacity and a high discharge voltage. In addition, the capacity of the battery packs has been increasing in recent years. To charge the battery packs having a large battery capacity and a high discharge voltage in a short time, high-output charging apparatuses are generally used.
The high-output charging apparatuses can shorten the charge time, but increase the temperature of electric components of the charging apparatuses. In addition, the high-output charging apparatuses cause the battery packs themselves to produce a large amount of heat. Moreover, when a battery pack is tried to be charged immediately after the battery pack is used in a high-output electric tool, the battery pack cannot be charged because the battery pack itself has a high temperature.
As countermeasures to these problems, there is proposed a charging apparatus which uses a cooling fan and forcefully cools the interior of the charging apparatus and a battery pack (for example, Patent Literature 1). This charging apparatus sends an airflow generated by the cooling fan to the interior of the battery pack and the interior of the charging apparatus, and thereby cooling heat-producing components of the battery pack and of the charging apparatus to suppress heat production.